Breast cancer is a type of cancer in which cells in the breast become abnormal and grow and divide uncontrollably. Normal cells divide, grow, and die on a continual, controlled basis. The nucleus of each cell contains genes made up of DNA that determines its lifespan. When cells grow uncontrollably, they will eventually form a mass, also called a tumor. Benign tumors are not cancer, they do not invade other types of tissue, but they may pose problems depending on their size and location if they grow large enough to interfere with a bodily function (such as blood or urine flow) or put too much pressure on an organ or nerve. Malignant tumors are made up of abnormal cells that are capable of invading nearby tissues. Cells from the original tumor may also break off and travel via the blood or lymph systems to distant location (metastasize).
Most breast cancers are slow-growing and by the time a lump can be felt, it may have been growing for 5 or 10 years. Early breast cancer usually has no symptoms and the earlier a tumor is found, the better the chance of survival. For these reasons it is extremely important for women to be screened regularly by mammography or ultrasound since they may identify a cancerous tumor before it can be felt. In addition, if a lump or thickening can be felt, it is vital to seek a medical evaluation right away.
There are different types of breast cancer. One type of breast cancer is ductal cancer. The duct cells form the tissue that drains breast milk to the nipple. There are many groups of ducts and they all drain together at the nipple. The cells that make up the ducts can become cancer cells. When cancer cells develop in the duct tissue the cancer is called “ductal carcinoma in situ. Ductal cancer cells can grow through the ducts and into nearby tissues. When breast cancer cells grow beyond the ducts, it is called invasive ductal carcinoma. The cancer cells started in the duct tissue and grew into other tissues such as lymph or blood vessels or into the supporting (or stromal) tissue around the ducts. Invasive ductal cancers are measured by tumor size, which is important when planning each patient's treatment. Invasive ductal cancer means the cancer cells have invaded the tissue next to the milk ducts. It also means the cells can spread from the original tumor to nearby lymph nodes and/or to other organs (lungs, liver, bones).
A second type of breast cancer is called lobular carcinoma. The lobular tissue is the milk-producing gland tissue of the breast. It is arranged in clusters or rings of cells. Each cluster is called a gland. The glands produce the breast milk that goes into the ducts. Cancer that starts in the lobular tissue is different from ductal cancer. Lobular carcinoma in situ (LCIS) is an area of precancerous cells that are unlikely to become invasive cancer. But these abnormal cells in a lobule show that the woman has a high risk of developing invasive breast cancer. Lobular breast cancer is more likely to develop in both breasts than is ductal cancer.
There are some other types of breast cancer that affect women and do not fit into the ductal or lobular categories. These are described briefly below:
1) Inflammatory Breast Cancer—this type of breast cancer starts as a rash in the skin of the breast. It is uncommon and aggressive.
2) Sarcoma or Paget's disease of the breast-another rare form of breast cancer that does not begin with abnormal cells of breast tissue. It starts in the support tissues of the breast.
3) Lymphoid breast cancer—this is a form of lymphoma, a cancer of the lymph tissues.
There are different ways of screening the body for anomalies including cancerous tissues. For example, when an x-ray picture is taken through an object, the three-dimensional interior appears only as a two-dimensional picture, the details from front to back of the object appear superimposed and the picture is difficult to interpret. One method of carrying out an examination of a body by X-radiation is known as tomography. In tomography, a source of radiation is orbited relative to the body being examined, about an axis in or near the body, while a plate or other screen sensitive to the radiation transmitted through the body is displaced in such a way that the elements in one plane of the body remain substantially stationary. One type of tomography is a computerized axial tomography scan (CAT scan). In a cat scan, a series of detailed pictures of areas inside the body, taken from different angles; the pictures are created by a computer linked to an x-ray machine. This approach is also called computed tomography (CT scan) or computerized tomography. A CT Scan or CAT Scan has the ability to image soft tissue, bone, and blood vessels. Unlike other medical imaging techniques, such as conventional x-ray imaging (radiography), CT enables direct imaging and differentiation of soft tissue structures, such as liver, lung tissue, and fat. CT is especially useful in searching for large space occupying lesions, tumors and metastasis and cannot only reveal their presence, but also the size, spatial location and extent of a tumor. The CT scanner is a doughnut-shaped machine that uses advanced x-ray technology to take pictures of cross-sections of your body, called ‘slices.’ CT can examine areas that cannot be seen on regular x-ray examinations. CT scanners use x-rays, but the amount of radiation is kept to an absolute minimum.
Another method that is used to scan a body maps the absorption coefficient of a two dimensional slice of a body from a knowledge of the line integral of the absorption coefficient along all lines intersecting the slice. The map is prepared by a process involving the application of, for example, Fourier inverting techniques.
In a still other method, a small radio active source moves so as to follow the motion of a detector at the other side of the body. A representation of the section similar to a roentgenogram is produced by causing a thin line of light to be generated across the face of an open-shutter CRT screen to represent the line of view of the detector. The line of light is moved across the screen face to correspond to the detector motion, and the film holder rotated step-wise to correspond with the angle of the detector. The brightness of the line of light is varied according to the counting rate from the detectors so that the film ultimately records a picture built up from a series of overlapping lines of varying brightness.
In another approach of examining at least part of the interior of a body uses penetration radiation such as X or γ rays. In this approach radiation from an external source is transmitted through the body in a plurality of rays traversing a plurality of respective paths at an initial angle or initial mean angle. The rays constitute a first set of rays in a single planar slice of said body. The cross-sectional dimensions of each ray are small in relation to the dimensions of the body. Radiation from the external source is transmitted through the body in further sets of rays similar to the first set of rays. These further sets are disposed in the planar slice at angles or mean angles different from each other and from the initial angle or initial mean angle. The sets of rays are such that every element of a two-dimensional matrix of elements of the body in the planar slice is intersected by a group of the rays. The group of rays are different for the different elements of the array. From each ray emerging from the body an output signal is derived representing the sum of the transmissions or absorption in the elements of the body intersected by the ray. Thus, sets of output signals corresponding to the sets of rays are derived sufficient to obtain the transmission or absorption of each element of the resulting matrix. From the output signals, by a process of successive approximations, there are derived resultant signals representing the transmission or absorptions of the elements of the matrix. The derivation of the resultant signals typically includes the steps of deriving a difference signal responsive to the difference between each output signal and its reconstruction from the last approximations to the resultant signals, and adjusting the approximations to the respective resultant signals in response to the difference signal. Finally, in response to the resultant signals a representation of the transmissions or absorptions of the elements of the slice of the body is produced.
One of the problems in using the scanning devices is that the area being scanned should not be blocked by other parts of the body. As a result, when a scan is being taken as part of a breast cancer diagnosis, the patient's arms cannot block the area being scanned. In addition, because of the sensitivity of the devices and the small areas being scanned, patient movement must be minimized. As a result, the patient must typically be placed in a reclining position with the patient's arms raised away from the side of the body.
Prior art scanning devices usually include an arm rest. One typical arm rest is of the type sold by Q-Fix. This is a mechanical device which can be adjusted to a variety of positions to accommodate different patient sizes and conditions. One of the problems encountered in using arm rests of these types is that they are difficult to adjust. Because they are designed to adjust to a variety of positions both horizontally and vertically, there are a great number of potential permutations that are possible and a great deal of time is taken to adjust the arm rest to each patient.
Besides the complexity of the prior art devices, these devices also suffer from significant cost. Another issue with these devices is tied into the issue of cost is disposability. These devices must be cleaned after each use by a patient. This is time consuming and adds labor cost to the scan.
As a result, there is a need for an improved arm rest for use with scanning machines and the like that does not have the drawbacks of the prior art.